solar system – GOLLYGEE!

There is possibly a new ninth planet. And no, we’re not talking about bringing back Pluto, which was demoted to dwarf planet status in 2008.

Astronomers at Caltech have detailed evidence for the existence of a new ninth planet, beyond the orbit of Pluto. Professors Michael E. Brown and Konstantin Batygin noticed disturbances in the orbits of six objects in the Kuiper belt. The alignment of these orbits leads the researchers to believe that they are being influenced by a ninth planet, which orbits the sun so far away that it would take 15,000 years to orbit the Sun. Scientists predict that this new planet, which they are calling Planet X or Planet Nine, has a mass 10 times larger than Earth.

A recent survey of the solar system found far less dark matter than previous estimates. From Nature:

In their survey, Christian Moni Bidin of the University of Concepcion in Chile and his colleagues used the European Southern Observatory’s 2.2-metre telescope in La Silla and three other telescopes to weigh, in effect, an extended volume of space centred around the Sun. Although this area cannot be measured directly, the total mass within the volume can be inferred by its influence on the motions of stars that are passing through.

The researchers measured the velocity of more than 400 stars within 4,000 parsecs (13,000 light years) of the Sun in a limited volume — a 15-degree cone — below the flattened disk of the Milky Way Galaxy, and then used those observations to extrapolate the velocities of stars on the other side of the disk, above the plane. This volume is approximately four times greater than that surveyed by other teams in previous studies.

The researchers found that at most, only about one-tenth the amount of dark matter predicted by models could exist in the volume of space they examined, Moni Bidin says.

GOLLYGEE!

Tag: solar system

planet x

dark matter doesn’t matter?